Investigation of Melting Behavior of Low-Enthalpy Glass Batches

2014 ◽  
Vol 608 ◽  
pp. 311-315 ◽  
Author(s):  
Kanit Tapasa ◽  
Ekarat Meechoowas ◽  
Usuma Naknikham ◽  
Tepiwan Jitwatcharakomol
Keyword(s):  
Raw Materials ◽  
Glass Batch ◽  
Glass Melting ◽  
Kinetic Property ◽  
Melting Process ◽  
Soda Lime ◽  
Melting Behavior ◽  
Soda Lime Glass ◽  
Chemical Heat ◽  
Heat Demand

Batch modification with low-enthalpy raw materials is the effective approach for reducing the glass melting energy. In the previous study, it was found that introducing wollastonite (CaSiO3) as a source of CaO instead of calcium carbonate (CaCO3) in the soda-lime glass batch can fasten the melting process. It is because the modified batch with CaSiO3 has lower chemical heat demand, ΔHochem, which is equivalent to the standard heat of batch-to-melt conversion. In order to investigate the kinetic property of the modified batch, the melting behaviour of 2 kg modified batch was studied. The results showed that the temperature of the modified batch increased at a faster rate than the original batch. The properties of the glass from the modified are also similar to the original batch.

Study of Melting Ability of Granulated Glass Batch

2016 ◽  
Vol 690 ◽  
pp. 272-275
Author(s):  
Kanit Tapasa ◽  
Ekarat Meechoowas ◽  
Suwannee Thepbutdee ◽  
Amorntep Montreeuppathumb
Keyword(s):  
Glass Furnace ◽  
Waste Heat ◽  
Raw Materials ◽  
Glass Batch ◽  
Glass Melting ◽  
Glass Production ◽  
Melting Process ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Preheating Temperature

In the conventional soda-lime glass production, loose raw materials are normally mixed into a glass batch for melting. Dusting and segregation of the loose glass batch are always occurred during the melting process inside the glass furnace. Also, the loose glass batch has low thermal conductivity which limits the glass melting ability and pulling rate of the glass furnace. Granulation and preheating of glass raw materials have been proposed to solve the problems. In this study, the granulated soda-lime glass batch (SiO2 50% Na2CO3 22.5% CaCO3 12% NaAlSi3O8 9.5% BaCO3 2.5% ZnO 1.75% Sb2O3 1% and K2CO3 0.75% by weight) was prepared to study the melting ability in an electric furnace. The granulated batch was also preheated at 500-600°C before melting. The preheating temperature was matched to the temperature of flue gas at the bottom of the stack in the glass furnace. The purpose behind this was aiming to recover the waste heat from the furnace. The experiment exhibited the increased melting ability for the granulated-preheated glass batch

Alternative Soda-Lime Glass Batch to Reduce Energy Consumption

2013 ◽  
Vol 545 ◽  
pp. 24-30 ◽  
Author(s):  
Ekarat Meechoowas ◽  
Kanit Tapasa ◽  
Tepiwan Jitwatcharakomol
Keyword(s):  
Melting Temperature ◽  
Raw Materials ◽  
Glass Batch ◽  
Heat Content ◽  
Melting Process ◽  
Soda Lime ◽  
Raw Material ◽  
Soda Lime Glass ◽  
Kinetic Properties ◽  
Atmosphere Temperature

Soda-lime glass is produced by melting sand (SiO2), soda ash (Na2CO3), lime stone (CaCO3) together with effective additives such as dolomite (CaMg(CO3)2) and an important structural modification, alumina (Al2O3) in which the melting temperature is very high around 1500°C. With this reason, to dissolve alumina, high amount of energy is needed. Consequently, one of possibilities to reduce the melting energy is replacing alumina by the raw material with a lower enthalpy of melting. The heat required for melting the batch of raw materials from atmosphere temperature to melting temperature is called exploited heat (Hex), which can be calculated from chemical enthalpy (H°chem) and heat content (Hmelt) at reference temperature (Tex). From thermodynamic approach, chemical enthalpy of alumina is higher than feldspar (KAlSiO3) or pyrophyllite (Al2Si4O10(OH)2). For the glass batch with alumina, the calculated exploited heat is 540 kWh/ton while the batch with feldspar or pyrophyllite is lower, namely 534 and 484 kWh/ton, respectively. This means that the melting process can be emerged easier than the batch with alumina because the melting point of feldspar is around 1200°C and pyrophyllite dehydroxylates around 900°C. The kinetic properties of batch melting were investigated by Batch-Free Time method, which defines the melting ability of the modified batch. According to thermodynamic calculation, it was found that both alternative batches were melted easier. The study showed that feldspar or pyrophyllite could be used instead of alumina without significant changes in glass chemical composition and physical properties. The concern of using feldspar or pyrophyllite is the quantity of minor impurities which affect to the color appearance especially in clear glass products.

Increasing the Melting Ability of Glass Batch by Batch Modification

2013 ◽  
Vol 770 ◽  
pp. 128-131 ◽  
Author(s):  
Ekarat Meechoowas ◽  
Konnika Tui-Ai ◽  
Kanit Tapasa ◽  
Usuma Naknikham ◽  
Tepiwan Jitwatcharakomol
Keyword(s):  
Aluminium Hydroxide ◽  
Raw Materials ◽  
Glass Batch ◽  
Soda Lime ◽  
Free Time ◽  
Soda Lime Glass ◽  
Lower Melting

The soda-lime glass with the composition of 74SiO2-18Na2O-6CaO-B2O3-Al2O3 thermodynamically requires the exploited heat of 557 kW/ ton of glass to transform raw materials into glass. The objective of this project is to modify the soda-lime glass batch by using wollastonite instead of limestone and pyrophyllite instead of aluminium hydroxide. The exploited heat of the batch with wollastonite is reduced to 546 kW/ton of glass while the batch with wollastonite and pyrophyllite is decreased to 550 kW/ton of glass. According to Batch-Free Time testing, it is found that the melting ability of both modified batches is higher than of the original batch, while the properties of glass are slightly changed. This implies that the modified batch requires a lower melting energy than the original batch.

Chemical Reactions in a Soda-Lime Silicate Batch

2008 ◽  
Vol 39-40 ◽  
pp. 459-464
Author(s):  
František Novotný ◽  
Rostislav Lošot
Keyword(s):  
Chemical Reactions ◽  
Raw Materials ◽  
Glass Melting ◽  
Reaction Pathway ◽  
Melting Process ◽  
Soda Lime ◽  
Reaction Pathways ◽  
Technological Properties ◽  
Present Contribution ◽  
Principal Reaction

Primary chemical reactions among the raw materials composing the batch give rise to various transitory intermediate products. Their physical properties influence the character of the glass melting process. The reaction pathway can be controlled by selecting the conditions, e.g. the grainsize composition of raw materials or the heating rate, which will influence the efficacy of the subsequent fining process. The present contribution describes practical technological properties of a couple of principal reaction pathways. A relationship between the practical monitoring of the actual glass melting process and the occurrence of peculiar chemical specimens is also mentioned.

The Glass Related Properties of the SIBOR® Oxidation Protective Coating on Molybdenum Alloys

2008 ◽  
Vol 39-40 ◽  
pp. 613-618
Author(s):  
Hans Peter Martinz ◽  
Brigitte Nigg ◽  
Jiri Matej ◽  
Manfred Sulik ◽  
Heike Larcher
Keyword(s):  
Protective Coating ◽  
Glass Melting ◽  
Soda Lime ◽  
Atmospheric Plasma ◽  
Soda Lime Glass ◽  
Melting Tank ◽  
Heating Rates ◽  
Molybdenum Alloys ◽  
Opal Glass ◽  
Heating Up

The SIBOR® (Si-10B-2C) oxidation protective coating was applied onto molybdenumand molybdenum – 3 wt% zirconia samples by APS (= Atmospheric Plasma Spraying) with a subsequent heat treatment. Then the coated samples were submitted to ramp oxidation tests with heating rates of 10°C / hour up to a temperature of 1450°C. This procedure simulates the heating up of a glass melting tank where SIBOR® coated parts are most frequently used. Some of the samples which could be oxidized without any defect were then immersed in various molten glasses to determine the dissolution rate of the SIBOR® substrate system. This simulates the situation when the glass melting tank is filled and operated with molten glass. SIBOR® proved to be an excellent oxidation protective coating for the molybdenum – zirconia – material like for pure molybdenum. The coating was fairly good dissolved by opal glass and – slightly less – by soda lime glass. With borosilicate glass a much slower interaction was found. In all cases some discolouration and bubbles were found in the glasses after one week.

scholarly journals Melting Process and Viscosity of Bohemian Historical Glasses Studied on Model Glasses

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 829
Author(s):  
Karolína Pánová ◽  
Kristýna Jílková ◽  
Dana Rohanová ◽  
František Lahodný ◽  
Dagmar Galusková ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Production Process ◽  
Technological Progress ◽  
Raw Materials ◽  
Glass Melting ◽  
Melting Process ◽  
Melting Characteristics ◽  
Thermal Dilatation ◽  
Materials Used ◽  
Insight Into

Analyzing the chemical composition of archaeological glasses can provide an insight into their provenance and raw materials used in their making. However, to the authors’ knowledge, the historical production process itself and melting characteristics of the glasses have not yet been extensively investigated. The main focus of this paper is to describe the melting process of three main types of Bohemian historical glasses: Gothic (14th–1st half of 16th c.); Renaissance (16th–17th c.); and Baroque (end of 17th–18th c.). The model glasses were prepared from natural raw materials and processes that take place during melting were investigated using optical microscopy, SEM-EDS, XRD, and DTA-TG methods. Furthermore, the viscosity of model glasses and thermal dilatation was measured and used to calculate the reference viscosity points. The results illustrate the complexity of historical glass melting, as well as the technological progress between different periods.

Glass Batch Modification to Improve the Weathering Resistance in Soda-Lime Silicate Glass

2019 ◽  
Vol 798 ◽  
pp. 206-211
Author(s):  
Ekarat Meechoowas ◽  
Parida Jampeerung ◽  
Kanit Tapasa ◽  
Usanee Pantulap ◽  
Tepiwan Jitwatcharakomol
Keyword(s):  
Glass Surface ◽  
Glass Batch ◽  
Glass Structure ◽  
Glass Production ◽  
Soda Lime ◽  
Tropical Region ◽  
Soda Lime Glass ◽  
Atmospheric Conditions ◽  
Two Samples ◽  
Weathering Resistance

The soda bloom - white stain on the glass surface – is an issue concerned in the glass manufacturing. It is because of high humidity and warm weather especially in the tropical region. The aim of this study was to modify glass batch to increase the weathering resistance for soda-lime glass. The weathering resistance of glass was measured by using the sodium (Na) leach technique according to the ISO 719. In principle, the strength of glass structure decreases with increasing Na content. The reactions start when free Na+ions moving to the glass surface and react with moisture from the surroundings. From this reason, the soda bloom occurs during storage lifetime. Two samples of glasses as described in Table 1 were modified with dolomite (CaMg (CO3)2) or alumina (Al2O3) to reduce the sodium free ion on the glass surface and increase the strength of glass structure Table 1: The glasses compositions All glasses were melted at 1500oC for 3 hours and annealed at 570°C. In glass structure, magnesium (Mg) and aluminium (Al) are network modifiers that can improve the structural strength and the weathering resistance of glass. The weathering resistance is in the inverse relationship with the weight of Na2O in mg per 50 ml of water according to theISO 719. The results showed that the weathering resistance increased with increasing dolomite or alumina contents. The experiments of increasing dolomite from 0 to 18 wt.% in a replacement of calcite showed the result that indicated the weight of Na2O in mg per 50 ml of water decreased from 0.53 to 0.41 mg, and the glass with increasing alumina from 0 to 1 wt.% showed that the weight of Na2O in mg per 50 ml of water decreased from 0.80 to 0.39 mg. According to the weathering chamber test under the cyclic atmospheric conditions of 60% and 80% relative humidity, and the cyclic temperatures of 20°C and 32 °C for 14 days, the glasses with more than 12 wt.% dolomite or more than 1 wt.% alumina did not generate the white stains on the surface. This process can be applied in the glass production. The satisfied result was found in the glass sample with 12 wt.% dolomite and 1 wt.% alumina. The weight of Na2O per 50 ml H2O reduced to 0.43 and 0.41mg, respectively, and the storage time increased from 3 months to 6 months without soda bloom.

Effect of Mechanical Activation on the Heat of Fusion of a Conventional Batch Used for the Manufacture of Float Glass

MRS Advances ◽  
2019 ◽  
Vol 4 (57-58) ◽  
pp. 3171-3180
Author(s):  
J. López-Cuevas ◽  
G. Vargas-Gutiérrez ◽  
P.P. Rodríguez-Salazar ◽  
S.R. Ruiz-Ontiveros
Keyword(s):  
Mechanical Activation ◽  
Raw Materials ◽  
Chemical Reactivity ◽  
Melting Process ◽  
Soda Lime ◽  
Initial Mixture ◽  
Float Glass ◽  
Heat Of Fusion ◽  
Activation Process ◽  
Batch Melting

ABSTRACTAn initial mixture of raw materials (batch) typically used for the manufacture of conventional soda-lime float glass was subjected to a mechanical activation process for 30 or 60 minutes in a planetary ball mill. An intensification of the chemical reactivity of the batch, which was directly related with the increase in the milling time, was observed. This accelerated the chemical reactions that took place during the batch melting process between sodium, calcium and magnesium carbonates and other components of the mixture, which happened at significantly lower temperatures with respect to the batch without mechanical activation. The heat of fusion of the batch, estimated using a methodology previously reported in the literature, indicated that the mechanical activation given to the initial mixture of raw materials decreased the energy consumed during the batch melting. This was also evidenced by a decrease in the temperature at which the release of CO2 ended, which was considerably larger than that previously reported in the literature based solely on the decrease in the particle size of a batch of similar composition achieved by dry sieving.

Fabrication of Glass Furnace for Research Scale: Case Study for Soda Lime Silicate Melting Process

2014 ◽  
Vol 979 ◽  
pp. 409-412
Author(s):  
K. Boonin ◽  
S. Tuscharoen ◽  
J. Kaewkhao ◽  
N. Sangwaranatee
Keyword(s):  
Optical Properties ◽  
Physical Properties ◽  
Heat Loss ◽  
Glass Furnace ◽  
Energy Cost ◽  
Raw Materials ◽  
Melting Process ◽  
Soda Lime ◽  
Made In

In this work, glass furnace for research scale has been fabricated using domestic raw materials. Furnace was designed and assembled in laboratory for reduce the heat loss due to openings when load out crucible from furnace, reduce energy cost and increase the number of glass samples that can be made in one working time. Glasses based soda lime silicate formulas have been prepared using the normal melt-quench technique for furnace testing. The result found that good optical properties and physical properties of glasses were obtained.

IDENTIFICATION OF ABNORMAL PHASE AND ITS FORMATION MECHANISM IN SYNTHESIZING CHALCOGENIDE FILMS

2016 ◽  
Vol 23 (01) ◽  
pp. 1550081 ◽  
Author(s):  
KEGAO LIU ◽  
NIANJING JI ◽  
YONG XU ◽  
HONG LIU
Keyword(s):  
Raw Materials ◽  
Water Immersion ◽  
Energy Dispersive Spectrometer ◽  
Soda Lime ◽  
Preferred Orientation ◽  
Water Soluble ◽  
Soda Lime Glass ◽  
Photoelectric Conversion ◽  
Experimental Conditions ◽  
Chalcogenide Films

Chalcogenide films can be used in thin-film solar cells due to their high photoelectric conversion efficiencies. It was difficult to identify one abnormal phase with high X-ray diffraction (XRD) intensity and preferred orientation in the samples for preparing chalcogenide films by spin-coating and co-reduction on soda-lime glass ([Formula: see text]) substrates. The raw materials and reductant are metal chlorides and hydrazine hydrate respectively. In order to identify this phase, a series of experiments were done under different conditions. The phases of obtained products were analyzed by XRD and the size and morphology were characterized by scanning electron microscope (SEM) and atomic force microscopy (AFM). From the experimental results, first it was proved that the abnormal phase was water-soluble by water immersion experiment, then it was identified as NaCl crystal through XRD, energy dispersive spectrometer (EDS) and SEM. The cubic NaCl crystals have high crystallinity with size lengths of about 0.5–2[Formula: see text][Formula: see text]m and show a [Formula: see text]100[Formula: see text] preferred orientation. The reaction mechanism of NaCl crystal was proposed as follows: The NaCl crystal was formed by reaction of Na2O and HCl in a certain experimental conditions.

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